Conventional method and apparatus for turning up a tire structure member are disclosed, for example, in JP2001-525748A. This known apparatus includes a plurality of turn-up arms which are arranged as being spaced from each other in the peripheral direction, on both axially outer sides of a tire building drum. The turn-up arms are adapted to swing in the radial direction around the respective base ends separated from a bead lock body in a plane including the center axis of the tire building drum. A turn-up roller is rotatably supported by the tip end of each turn-up arm and adapted to achieve a rolling contact with the turn-up portion. A rubber band is fitted to the outside of the turn-up arms so that the turn-up arms are applied with urging swing force oriented radially inward. A moving means is provided for synchronously moving the turn-up arms axially inward, to thereby cause the turn-up arms to synchronously swing radially outward against the rubber band while the turn-up rollers are maintained in rolling contact with the turn-up portions, so that the turn-up portions are turned around the beads.
However, in such conventional method and apparatus for turning up a tire structure member, when the turn-up portion is turned, the swinging movement of the turn-up arm radially outward is performed by applying a moving force to the turn-up arm axially inward, so that the turn-up rollers are made to ascend along the main body portion. At this time, since the turn-up arms are swung against the resilient force of the rubber band, the turn-up rollers are strongly urged against the turn-up portions under a large reaction force from the rubber band. As a result, impressions (grooves) extending in the radial direction is generated in the outer surface of the turn-up portion. Such impressions tend to be considerably deep and cannot be erased even by vulcanization in some cases, giving rise to a problem that grooves extending in the radial direction are generated in sidewall portions of a product tire.
It is an object of the present invention to provide a method and an apparatus for turning up a tire structure member, capable of effectively restricting generation of grooves in a sidewall portion.